[tex-eplain] Incorporating url.sty

[geolsoft at mail.ru]

On Tue, Aug 23, 2005 at 04:16:38PM +0200, Karl Berry wrote:
> Do we end up calling the
> macro which actually executes the option for the package?  Or are we
> constructing a list that we pass when we input color.sty, as if we were
> really doing
> \usepackage[option1,option2]{color}

No, it is more like saving in some macro the code which has
to be executed in order to set an option, and later call
that macro upon call to \pkgoptions{...}{...}.  I might be
wrong, but I figured that LaTeX packages do something like
this for every option they support:

  \DeclareOption{hyphens}{\def\do at url@hyp{\do\-}}

By default, miniltx.tex just makes

  \let\DeclareOption\@gobbletwo

so all option declarations go to waste.  Instead, we
(re)define \DeclareOption to take the name of the option
(the first parameter), to construct a macro name using this
name (pkgoptions at PACKAGENAME@hyphens), and to define this
macro to the code (the second parameter).  Later on, after
the package will have been loaded, the user might call
\pkgoptions{option}{pkg} to have that macro called and the
option applied.

> (And BTW isn't xcolor better than and compatible with color?)

I don't know, I've never heard of it.  It is not even on my
system.  I am very backwards in this respect, I have a
Debian, and quite an old one :-O

>     BTW, why the first parameter to \pkgoptions is optional?
>     Does this call make any sense:  \pkgoptions{url}?
> 
> No, it doesn't make sense.  I was just thinking "\usepackage" syntax in
> my head.

Then, I think, if we don't make it optional, we should
change the order, too:

  \pkgoptions{PKG}{OPTION}

instead of

  \pkgoptions{OPTION}{PKG}

-- 
Best regards,
Oleg Katsitadze